the point being, we would have to run totally different move sets to what we run currently draco meteor? too inacurate hypnosis? no way fire blast? megahorn? stone edge? focus blast? all these moves will be useless as they wont hit enough meaning running weaker variants and imagine if a subber got DT going and you miss that ONCE it gets another and another then starts setting up and sweeps you, sounds like a possibilty to me
I'm going to reply to this because it's a perfect example of what I'm talking about. What you're saying is that you don't want to have to alter your team to deal with a new threat. That's your opinion about how the metagame should be. If you aren't willing to use moves like Yawn to get through DT or Encore/Taunt to get through Substitute, then you're opening yourself up to the Double Team/Sub strategy. Similarly, if you aren't willing to use Pokémon with Insomnia or a Sleep Talker, you're opening yourself up to sleep-inducing moves. If you're not willing to use a Steel-type, you're opening yourself up to being swept by Outrage.
Besides, Double Team and Substitute constitutes half of your moveset. What are you going to put in the rest? Chances are good that those two moves can be walled. Please read X-Act and Dragontamer's posts before arguing that Double Team is too powerful.
EDIT: Phalanx, please, please use periods as a personal favor to me. Maybe I'm just dense, but it took me a while to puzzle out where all the punctuation should have been in your post.